U.S. health officials unveiled new measures on Wednesday to carry out Ebola monitoring on anyone entering the country from the three nations at the center of West Africa’s epidemic, increasing precautions to stop the spread of the virus.

The U.S. Centers for Disease Control and Prevention (CDC) said that beginning Monday, travelers from Liberia, Sierra Leone and Guinea will be directed to check in with health officials every day and report their temperatures and any Ebola symptoms for 21 days, the period of incubation for the virus. The travelers will be required to provide emails, phone numbers and addresses for 21 days, and the information will be shared with local health authorities. They will also be required to coordinate with local public health officials if they intend to travel within the United States. If a traveler does not report in, local health officials will take immediate steps to find the person.

CDC Director Dr. Tom Frieden said the active monitoring program will remain in place until the outbreak in West Africa is over. The World Health Organization’s latest figures on Wednesday showed at least 4,877 people have died in the outbreak. Health officials have said that Ebola will remain an international threat until the epidemic in West Africa is brought under control.

“These new measures I’m announcing today will give additional levels of safety so that people who develop symptoms of Ebola are isolated early in the course of their illness,” Dr. Frieden said. “That will reduce the chance that Ebola will spread from an ill person through close contact and to healthcare workers.” The move builds upon enhanced screening of passengers from the three countries at major U.S. airports for international travel, but stops short of an outright travel ban advocated by some conservative lawmakers.

The Department of Homeland Security has said that beginning Wednesday travelers from Liberia, Sierra Leone and Guinea would be funneled to one of five major U.S. airports conducting enhanced screening for the virus. Six states account for nearly 70 percent of all travelers entering the United States from the affected countries: New York, Pennsylvania, Maryland, Virginia, New Jersey and Georgia.

The CDC said the active monitoring program affects anyone coming back from the region including CDC employees and journalists. The agency said all affected travelers when they enter one of the five airports will receive a care kit that contains tracking log, a pictorial description of symptoms, a thermometer, instructions on how to monitor their temperature and information on what to do if they experience symptoms.

In other developments, Ron Klain, the lawyer appointed by the White House to coordinate to coordinate the country’s response to the outbreak got to work on Wednesday. President Barack Obama was due to meet with Klain later in the day. Also on Wednesday, leading drugmakers announced a plan to accelerate development of an Ebola vaccine, with the eventual goal of producing millions of doses.

Meanwhile, earlier this week, the CDC released revised guidelines for healthcare professionals working with Ebola patients. This includes wearing personal protective equipment (PPE) that leaves no skin exposed and using a face mask and respirator during all contact with infected patients. The guidelines also call for the use of a a “buddy system” in which workers check each other as they come in and go out. Hospital workers also will be expected to exhaustively practice and demonstrate competence in both putting on and taking off PPE.

Only three Ebola cases have been diagnosed in the United States: Thomas Eric Duncan, a Liberian who fell ill after flying to the United States in September, and two nurses who treated him at Texas Health Presbyterian Hospital in Dallas. Duncan died on Oct. 8, while the two nurses are being treated at other hospitals. While the situation in the U.S. is under control, the outbreak continues to escalate in the three hardest hit countries. Experts have said the world could face 10,000 new cases a week within the next two months if authorities don’t take stronger steps to fight the deadly virus.

Vaccine Testing

On Tuesday, the World Health Organization said that tens of thousand of doses of experimental Ebola vaccines could be available for “real world” testing in West Africa as early as January. Currently, several vaccines are going through initial safety testing in humans to look for any potentially adverse effects. If the vaccines are declared safe, health officials said they would be used in trials in West Africa as soon as possible to test their effectiveness among tens of thousands — but not millions — of people.

The first human Ebola vaccine study began in September at the National Institutes of Health in Bethesda, Md., where the vaccine was developed. U.S. health officials say they expect to have preliminary data on safety and effectiveness by the end of this year. Human studies of this vaccine are also underway in the United Kingdom and the African nation of Mali, and it will be used in clinical trials in Switzerland by February, said Marie Paule Kieny, Assistant Director-General for Health Systems and Innovation at the WHO.

If the vaccine proves safe and effective in these early trials, the NIH vaccine could be shipped to West Africa early next year for “compassionate use,” even if it’s not yet approved, U.S. officials have said. The experimental vaccine could be made available to people at high risk for Ebola — such as health workers — just as companies have made the unapproved drugs ZMapp and TKM-Ebola available to infected patients.

GlaxoSmithKline has signed on to further develop the NIH vaccine and mass produce it. The company has said that it could produce up to 1 million doses by the end of 2015. The vaccine uses a safe version of a chimpanzee adenovirus, similar to a virus that causes respiratory illness in humans, to ferry genetic material into patients. Researchers hope the vaccine will stimulate patients’ immune systems to produce antibodies against Ebola.

Canada also has developed an Ebola vaccine and began shipping 800 vials to the WHO’s headquarters in Switzerland Monday. The shipment is expected to arrive Wednesday. That vaccine, which has been licensed to NewLink Genetics in Iowa, will be used for clinical trials in Switzerland, Germany and the African nations of Gabon and Kenya, Kieny said.

The Walter Reed Army Institute of Research in Maryland began human trials of the Canadian vaccine last week. That vaccine, known as a VSV vaccine, is made with a vesicular stomatitis virus, which belongs to the same family of viruses as rabies.

January would mark the first test of tens of thousands of doses of experimental vaccines in the hardest-hit nations in West Africa, the WHO said. However, public health experts have said that while such a development would be welcome, we cannot rely on vaccines to control the outbreak. Despite the hope that we can soon defeat Ebola with new drugs and vaccines, the reality is that it won’t be solved with a biomedical silver bullet, experts say. Our best tools to fight pandemic viruses are social institutions: hospitals, governments, and health organizations that supply the trained personnel and equipment to carry out the disease control measures that we know are effective.